Locomotive brake control apparatus suited for remote multiple unit operation

ABSTRACT

BRAKE CONTROL APPARATUS FOR THE LEAD LOCOMOTIVE OF A MULTIPLE UNIT LOCOMOTIVE CONTROL SYSTEM WHEREIN THE BRAKE VALVE ON THE LEAD LOCOMOTIVE IS MANUALLY OPERABLE CONVENTIONALLY TO CONTROL APPLICATION AND RELEASE OF THE BRAKES ON THE FORWARD PORTION OF THE TRAIN FROM THE LEAD LOCOMOTIVE AND ALSO TO EFFECT CORRESPONDING CONTROL (VIA RADIO-TRANSMITTED SIGNALS INITIATED BY MANUAL OPERATION OF THE BRAKE VALVE ON THE LEAD LOCOMOTIVE) OF THE BRAKES ON THE REMAINING PORTION OF THE TRAIN FROM THE BRAKE VALVE ON A SLAVE LOCOMOTIVE REMOTELY LOCATED IN THE TRAIN. DIFFERENTIAL-PRESSURE-OPERATED MASTER CONTROLLER SWITCH DEVICES, SELECTIVELY OPERATED IN CORRESPONDENCE TO THE MANUAL OPERATION OF EITHER THE AUTOMATIC OR THE INDEPENDENT BRAKE VALVE ON THE LEAD LOCOMOTIVE, ESTABLISH SUITABLE CONTROL CIRCUITRY FOR RADIO TRANSMISSION OF APPROPRIATE BRAKE CONTROL SIGNALS FROM THE LEAD TO THE SLAVE LOCOMOTIVE SO AS TO CAUSE A VARIATION OF THE PRESSURE IN THE EQUALIZING RESERVOIR PRESSURE ON THE SLAVE LOCOMOTIVE, OR A VARIATION OF THE PRESSURE IN THE BRAKE CYLINDERS ON THE SLAVE LOCOMOTIVE, IN CORRESPONDENCE WITH THE VARIATION EFFECTED ON THE LEAD LOCOMOTIVE BY THE RESPECTIVE BRAKE VALVE THEREON, THEREBY INITIATING AN APPLICATION OR A RELEASE OF THE BRAKES ON THAT PORTION OF THE TRAIN COUPLED TO SLAVE LOCOMOTIVE CONCURRENTLY WITH THAT INITIATED ON THAT PORTION OF THE TRAIN COUPLED TO THE LEAD LOCOMOTIVE, OR TO CAUSE INDEPENDENT APPLICATION AND RELEASE OF THE BRAKES ON THE SLAVE LOCOMOTIVE SUBSTANTIALLY SIMULTANEOUSLY WITH THAT ON THE LEAD LOCOMOTIVE.

United States Patent [72] Inventor John G. Cannon Allegheny, Pa. [21]Appl. No 834,835 [22] Filed June 19, 1969 June 28, 1971 Westinghouse AirBrake Company Wilmerding, Pa.

[45] Patented [73] Assignee [54] LOCOMOTIV E BRAKE CONTROL APPARATUSSUITE!) FOR REMOTE MULTIPLE UNIT Primary Examiner-Duane A. RegerAttorneys- Adelbert A. Steinmiller and Ralph W. Mclntire,

ABSTRACT: Brake control apparatus for the lead locomotive of a multipleunit locomotive control system wherein the brake valve on the leadlocomotive is manually operable conventionally to control applicationand release of the brakes on the forward portion of the train from thelead locomotive and also to effect corresponding control (viaradio-transmitted signals initiated by manual operation of the brakevalve on the lead locomotive) of the brakes on the remaining portion ofthe train from the brake valve on a slave locomotive remotely located inthe train. Differential-pressure-operated master controller switchdevices, selectively operated in correspondence to the manual operationof either the automatic or the independent brake valve on the leadlocomotive, establish suitable control circuitry for radio transmissionof appropriate brake control signals from the lead to the slavelocomotive so as to cause a variation of the pressure in the equalizingreservoir pressure on the slave locomotive, or a variation of thepressure in the brake cylinders on the slave locomotive, incorrespondence with the variation efi'ected on the lead locomotive bythe respective brake valve thereon, thereby initiating an application ora release of the brakes on that portion of the train coupled to theslave locomotive concurrently with that initiated on that portion of thetrain coupled to the lead locomotive, or to cause independentapplication and release of the brakes on the slave locomotivesubstantially simultaneously with that on the lead locomotive.

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SHEET 2 [1F 2 as 88d 87 I05 a salosl 4 j 75 WA INVENTOR. JOHN G. CANNONATTORNEY LOCOMOTIVE BRAKE CONTROL APPARATUS SUITED FOR REMOTE MULTIPLEUNIT OPERATION BACKGROUND OF THE INVENTION There are presently in use onsome American railroads socalled RMU (remote multiple unit) brakecontrol systems capable of effecting, via radio-communicated signals,simultaneous operation of brake controls on a slave locomotive locatedintermediate the length of a train by operation of brake controls on thelead locomotive. In one such brake control system, the lead locomotiveis provided, in addition to the usual engineers brake valve, with amanually operated pushbutton-type brake control console the manualoperation of which simultaneously effects electropneumatic control ofpressure in an equalizing reservoir and the brake pipe on the leadlocomotive and also, via radio-communicated signals, control of pressurein an equalizing reservoir and the brake pipe on the slave locomotive,whereby operation of the brake equipment on those cars located betweenthe slave locomotive and the end of the train occurs substantiallysimultaneously with operation of the brake equipment on those carslocated intermediate the lead and the slave locomotive. The additionalcontrol equipment to insure that a locomotive is adapted for use as thelead locomotive in RMU operation represents not only additionalequipment costs but additional difficulties in servicing and maintainingthe equipment.

Accordingly, it is the purpose of this invention to provide a locomotivecontrol equipment suitable for use on the lead locomotive in RMUoperation without the additional separate control equipment including amanually operated pushbuttontype brake control console.

SUMMARY OF THE INVENTION According to the present invention, alocomotive brake control equipment suited for RMU operation is provided,in which the conventional automatic and independent brake valves areemployed for RMU operation, that is for control of the brakes on thelead locomotive and on the slave locomotive in the same train, withoutthe addition of a separate pushbutton-type brake control console. Thisis made possible by the provision of two differential-pressure-operatedmaster controller switch devices the operation of which is controlled bythe respective selective manual operation of the handle of either theautomatic or the independent brake valve to its various brake controlpositions, in which the respective brake valve functions in its normalmanner to control the pressure in either the equalizing reservoir or inthe brake cylinder on the lead locomotive for brake control purposes andat the same time, via radio-communicated signals initiated by operationthereof, effect similar variation of the pressure in either theequalizing reservoir or the brake cylinder on the slave locomotive forrespectively effecting corresponding simultaneous brake control on thatportion of the train coupled to the slave locomotive or control of thebrakes on the slave locomotive or locomotives only.

In the accompanying drawings:

FIG. 1 is a diagrammatic view of a locomotive brake control equipmentconstructed in accordance with one embodiment of the invention when thislocomotive is used as the lead locomotive in RMU operation.

FIG. 2 is an enlarged diagrammatic view of the automatic and independentbrake valves shown in FIG. 1.

FIG. 3 is a partial diagrammatic view of a locomotive brake controlequipment constructed in accordance with a second embodiment of theinvention when this locomotive is used as the lead locomotive in RMUoperation it being understood that the remainder of the equipment (notshown) is the same as that shown in FIG. 1.

As shown in FIG. 1 of the drawings, the conventional control equipmentheretofore provided on a locomotive when it is used as the leadlocomotive in remote multiple unit operation is modified by theinclusion of two differential-pressureoperated master controller switchdevices I and 2 and a fluidpressure-operated switch 3, and theelimination of the heretofore known and used manually operable brakecontrol console which embodied a plurality of pushbutton-type ofswitches that were manually operated to effect brake applications andbrake releases on the plurality of locomotives and cars comprising thetrain, it being understood that operation of the brake equipment on theslave locomotive and those cars comprising the portion of the traincoupled to the slave locomotive is effected via radio-transmittedsignals.

The brake control equipment constituting the present invention furthercomprises, for pneumatically controlling the brakes on the leadlocomotive, a brake cylinder 4, a main reservoir 5, an auxiliaryreservoir 6, a control reservoir 7 which is combined with a selectorvolume reservoir 8 into a two-compartment reservoir, a brake pipe 9 thatextends from end to end of the locomotive and at one end is coupled tothe train brake pipe by the usual hose and hose couplings, an engineersautomatic brake valve 10 operative to control the pressure in the brakepipe 9, an independent brake valve 11 that is secured to a pipe bracket12 of the automatic brake valve 9 by any suitable means (not shown) forcontrolling the brakes on the locomotives independently of the brakes onthe cars in the train and a fluid pressure brake control valve 13 thatis connected by a branch pipe 14 to the brake pipe 9.

In order to effect operation of the brake equipment on the slavelocomotive via radio signals transmitted thereto from the leadlocomotive, the brake control equipment embodying the present inventionfurther includes a function selector unit 15 having a plurality ofelectrical relays.

The pickup circuits of two of these relays are controlled by thedifferential-pressure-operated master controller switch device 1, andthe pickup circuits of two other of these relays are controlled by thedifierential-pressure-operated master controller switch device 2. Thepickup circuit of a fifth one of these relays is closed in response tothe supply of fluid under pressure to the fluid-pressure-operated switch3 in a manner hereinafter explained.

For transmitting radio signals to the slave locomotive, the presentinvention also includes a coding system 16 for receiving the outputinformation of the function selector unit 15 and preparing thisinformation for transmittal to the slave locomotive via a radiotransmitter 17 having an antenna 18. This brake equipment on the leadlocomotive further comprises a radio receiver I9 for receiving viaantenna 18 information in the form of radio signals transmitted from theslave locomotive regarding the status of this locomotive and convertingthese radio signals to electrical inputs which are fed to a decodingsystem 20 that in turn transmits the information regarding the slavelocomotive to the function selector unit 15 which coordinates thisinformation and furnishes it to a selector and indicator console 21 fordisplay.

Since the difierential-pressure-operated master controller switchdevices 1 and 2 are identical in construction, a description of one willsuffice for both, it being understood that corresponding parts aredenoted by the same reference numeral.

As shown in detail in FIG. 1, the differential-pressureoperated mastercontroller switch device 1 comprises a sec tionalized casingconstituting a pair of cuplike casing sections 22 and 23 between whichis clamped the outer periphery of a diaphragm 24 by any suitable means(now shown).

The diaphragm 24 cooperates with the casing sections 22 and 23 to formwithin the switch device I and on the respective opposite sides of thediaphragm 24 a pair of chambers 25 and 26.

The end of each of the cuplike casing sections 22 and 23 is providedwith a central bore 27 which at one end opens into the respectivechambers 25 and 26. Slidably mounted in the bores 27 is a stem 28 thatextends through the central opening provided in the diaphragm 24. Thatportion of the stem 28 disposed within the chamber 26 is provided with acollar 29 that on its left-hand side forms a shoulder against whichrests the inner periphery of the diaphragm 24 which is clamped againstthis collar by a nut 30 that has screw-threaded engagement with screwthreads formed on a portion of the stem 28 that is adjacent theleft-hand side of this collar 29.

Secured by any suitable means to the respective opposite ends of thestem 28 are a pair of movable contacts 31 and 32. Upon movement of thestem 38 in the direction of the left hand, the movable contact 31 ismoved into circuit-closing contact with a stationary contact 34 that iscarried by a plate 35 that is constructed of any suitable insulatingmaterial which, for example, may be rubber. The plate 35 is bonded orotherwise secured to a switchbox 36 in which the contacts 31 and 34 aredisposed and which is anchored to the casing section 22 by any suitablemeans (not shown).

Likewise, upon movement of the stem 28 in the direction of the righthand, the movable contact 32 is moved into circuitclosing contact with asecond stationary contact 37 that is carried by a second insulatingplate 35 identical to the first and secured in like manner to a secondswitchbox 36 in which the contacts 32 and 37 are disposed and which isanchored to the casing section 23 by any suitable means (now shown).

In each of the switch devices 1 and 2 the stationary contacts 34 areconnected to a positive power supply wire 38 by a wire 39 that extendsthrough the corresponding insulation plate 35 and an opening provided inthe side of the switchbox 36 to which the respective plate is secured.Likewise, the stationary contacts 37 are connected to the power supplywire 38 by a wire 40 which in like manner extends through thecorresponding insulation plate 35 and switchbox 36.

The movable contact 31 of the switch device 1 is connected by a wire 41having a loop therein to an automatic brake application relay (notshown) in the function selector unit 15 to cause energization or pickupof this relay. Whenever this relay is thus picked up, transmission ofthe automatic brake application command signal to the slave locomotiveis made via radio-transmitted signals effected by operation of thecoding system 16, transmitter 17 and antenna 18.

The movable contact 31 of the switch device 2 is connected by a wire 42having a loop therein to an independent quickrelease relay (not shown)in the function selector unit 15 to cause energization or pickup of thisrelay. Whenever this relay is thus picked up, transmission of theindependent brake release command signal to the slave locomotive is madevia radio-transmitted signals effected by operation of the coding system16, transmitter 17 and antenna 18.

The movable contact 32 of the switch device 1 is connected by a wire 43having a loop therein to an automatic brake release relay (not shown) inthe function selector unit 15 to cause energization or pickup of thisrelay. Whenever this relay is thus picked up, transmission of theautomatic brake release command signal to the slave locomotive is madevia radiotransmitted signals effected by the coding system 16, transmitter 17 and antenna 18. When this automatic brake release commandsignal is received on the slave locomotive it effects energization of asolenoid coil of a brake-valve-charging cutout spool valve which isthereupon moved to a position to release fluid under pressure from apressure chamber of a brake pipe cutoff valve of the automatic brakevalve on the slave locomotive. Upon this release of fluid under pressurefrom the brake pipe cutoff valve on the slave locomotive, the automaticbrake valve 10 on this locomotive is rendered effective to supply fluidunder pressure to the train brake pipe. Assuming that the brake valve 10on the lead locomotive is in its release position, the supply of fluidunder pressure to the train brake pipe is now simultaneously effected bythe operation of the automatic brake valve 10 on both the locomotives inthe train, in a manner hereinafter more fully described, until the trainbrake pipe is charged to the normal pressure carried therein which maybe, for example, 70 pounds per square inch.

The movable contact 32 of the switch device 2 is connected by a wire 44having a loop therein to an independent brake application relay (notshown) in the function selector unit to cause energization or pickup ofthis relay. Whenever this relay is thus picked up, transmission of theindependent brake application command signal to the slave locomotive ismade via radio-transmitted signals effected by the coding system 16,transmitter 17 and antenna 18.

The automatic brake valve 10 and the independent brake valve 11 are bothsecured to the pipe bracket 12 and thus constitute a 26-C type ofself-lapping brake valve manufactured by the Westinghouse Air BrakeDivision of Westinghouse Air Brake Company, a subsidiary of AmericanStandard, Inc.

The automatic brake valve 10, as shown in FIG. 2 of the drawings,comprises a relay valve 45, a self-lapping regulating or control valve46, a suppression valve 47, an equalizing reservoir cutoff valve 48, amanually positionable selector valve 49 for selectively conditioning thebrake valve 10 for effecting either direct release operation of thebrake control valve on each car in a train of cars hauled by alocomotive provided with this automatic brake valve 10, if each car isprovided with a direct release-type brake control valve, or graduatedapplication and graduated release operation of the brake control valveon each car, if each car is provided with a graduated release-typecontrol valve, for cutting out control of brake pipe pressure by thebrake valve 10 for multiple unit or trailing (pusher) unit operation, orfor conducting a brake pipe leakage test, a vent valve, an emergencyvalve, and a brake pipe cutoff valve, the latter three not being shownin FIG. 2 since they form no part of the present invention.

The independent brake valve 11 comprises a self-lapping valve unit 50which may be of any standard construction and therefore, will not bedescribed in detail herein. The independent brake valve 11 furthercomprises a differential area piston-type independent release valve 51,reciprocal in a direction at right angles to the axis of theself-lapping valve unit 50. This release valve 51 has small and largerdiameter ends which are exposed to atmospheric pressure and hastherebetween an annular chamber 52 which is constantly open to the mainreservoir 5 via a passageway and corresponding pipe 53. A bias spring 54acting on the small end of the release valve 51 and assisted by mainreservoir pressure in the annular chamber 52 urges the release valve 51to a normal position in which it is shown in FIG. 2. In this position,an actuating passageway 55 is connected to an atmospheric vent port 56via a peripheral annular groove 57 formed on the release valve 51. Thisactuating passageway 55 is connected by a correspondingly numbered pipeto the release selector valve portion of the quick-release valve whichconstitutes a part of the hereinbefore-mentioned brake control valve 13(FIG. 1) comprising a part of the brake control equipment on the leadlocomotive to provide for effecting an independent release of anautomatic brake application on this locomotive.

In order to provide for substantially simultaneously effectingtransmission of the independent brake release command signal to theslave locomotive to effect a release of the brakes only on thislocomotive subsequent to the engineer effecting a brake application onall the locomotives and cars in the train by use of the automatic brakevalve 10, one end of a pipe 58 is connected to the pipe 55 intermediatethe ends thereof and the opposite end is connected to afluid-pressure-operated switch 59. In the closed position of normallyopen contact 60 of switch 59, a circuit is established between a wire 61that is connected to the hereinbefore-mentioned power supply wire 38 anda wire 62 that is connected to the wire 42 intermediate the endsthereof. As hereinbefore stated, the wire 42 is connected to theindependent quick-release relay in the function selector unit 15.Therefore, closing of contact 60 causes energization or pickup of thisrelay which, when picked up effects transmission of the independentbrake release command signal to the slave locomotive.

A brake valve handle 63 is hinged on a pin 64 and also carries a roller65, which, upon manual depression of the handle 63 to rock it about thepin 64, acts through a pusher 66 to shift the release valve 51 to anindependent brake release position against the pressure of the spring 54and the fluid under pressure from the main reservoir acting in theannular chamber 52. In this depressed position, the peripheral annulargroove 5 7 connects the main reservoir passageway 53 to the actuatingpassageway and pipe 55 for charging the latter to effect an independentrelease of an automatic brake application on the locomotives in thetrain in a manner hereinafter described in detail.

As shown in the drawings, opening into the chamber 25 in the switchdevice 1 is one end of a pipe 67, the opposite end of which is connectedto a corresponding passageway in the pipe brake 12 which passagewayextends through the pipe bracket 12 and sectionalized casing of thebrake valve and opens into a chamber 63 (FIG. 2) at the left-hand sideof a diaphragm 69 of the hereinbefore-mentioned relay valve .45. Openinginto that portion of the passageway 67 in the pipe bracket 12 is apassageway 70 that is connected by a corresponding pipe to an equalizingreservoir 71 (FIGS. 1 and 2) via a choke 72 disposed in this pipe.Connected to the pipe '70 between the equalizing reservoir 71 and thechoke 72 is one end or" a pipe 73 the opposite end of which opens intothe chamber 26 in the switch device 1. Connected to the pipe 7t! betweenthe choke 72 and the pipe bracket 12 is one end of a pipe 74 that at itsopposite end is connected to a correspond ing passageway in the pipebracket 12. This passageway extends through the hereinbefore-mentionedequalizing reservoir cutoff valve 48, while it is in its open position,and opens into a delivery chamber 75 (FIG. I) in the control valve 46 ofautomatic brake valve It).

From the foregoing, it is apparent that fluid under pressure flows fromthe delivery chamber 75 of the control valve 46 to the chamber 25(FIG. 1) in the switch device 1 at an unrestricted rate via passagewayand pipe 74, pipe and passageway 70 and passageway and pipe 67. Fluidunder pres sure also flows at an unrestricted rate from the passageway67 to the chamber 68 in the relay valve 45.

Furthermore, it is apparent that fluid under pressure flows from thedelivery chamber 75 to the chamber 26 in the switch device I at arestricted rate determined by the size of the choke 72 via passagewayand pipe 74, pipe 70, choke 72 and pipe 73. Fluid under pressure alsoflows at a restricted rate from the choke 72 to the equalizing reservoir71 via the pipe 70.

Opening into the chamber 25 in the switch device 2 is one end of a pipe76 that at its opposite end is connected to a corresponding passagewayin the independent brake valve II which passageway opens into a deliverychamber 77 (FIG. 2) in the self-lapping valve unit 50 of the independentbrake valve 11. Connected to the pipe 76 (FIG. 1) intermediate the endsthereof is one end ofa pipe 78 having a choke 79 therein. The oppositeend of the pipe 78 opens into the chamber 26 in the switch device 2. Avolume reservoir 80 is connected to the pipe 78 on the downstream orright-hand side of the choke 79 by a pipe 81 the purpose of this volumereservoir 80 being to provide stability for the switch device 2.

In order to provide for an independent brake application and asubsequent independent release of the brakes on the lead locomotive bymanual operation of the independent brake valve 11, one end of a pipe 82is connected to the pipe 76 intermediate the ends thereof and theopposite end is connected to one inlet ofa double check valve 83. Theother inlet of this double check valve 83 is connected by a pipe 84 tothe brake cylinder port of the hereinbefore-mentioned brake controlvalve 13, and the outlet of this double check valve 83 is connected by ashort pipe 85 to the brake cylinder 4.

As shown in FIG. 2 of the drawings, a chamber 86 in the relay valve 45and at the right-hand side of the diaphragm 69 is connected to thehereinbefore-mentioned brake pipe 9, (FIG. 1) via a choke 87 and apassageway and corresponding pipe 88. A branch 88a (FIG. 2) of thepassageway 88 opens into the delivery chamber 89 of the relay valve 45.Consequently, the right-hand side of the diaphragm 69 is subject tobrake pipe pressure in the chamber 86 and the left-hand side of thisdiaphragm is subject to equalizing reservoir pressure in the chamber 68.Accordingly, the relay valve 45 is operative in response to variationsof pressure effected in the equalizing reservoir 71 by operation of thecontrol valve 66 to effect a corresponding variation of pressure in thebrake pipe 9.

In order that the engineer may always be able to quickly determine thetrue pressure in the equalizing reservoir 71, the usual equalizingreservoir pressure gauge 90 is connected by a pipe 91 to the pipe 70between the equalizing reservoir 71 and the choke 72.

As shown in the drawings, one end ofa pipe 92 is connected to thehereinbefore-mentioned fluid-pressure-operated switch 3 and the oppositeend of this pipe is connected to a corresponding passageway in theautomatic brake valve 10 which passageway leads to an emergency valve(not shown) in this brake valve 10. It will be understood that while ahandle 93 of the automatic brake valve 10 occupies all of its positionsexcept its emergency position the emergency valve occupies acorresponding position in which it establishes a communication betweenthe pipe and corresponding passageway 92 and atmosphere so that fluidunder pressure is completely vented from the fluid-pressure-operatedswitch 3. It will be further understood that, upon manual movement ofthe handle 93 of the automatic brake valve 10 to its emergency position,the emergency valve in this brake valve 10 is moved to a correspondingemergency position in which it establishes a communication through whichfluid under pressure may flow from the main reservoir 5 to the switch 3via pipe and passageway 53, a passageway 941 (FIG. 2), a peripheralannular groove (not shown) on the emergency valve, and the passagewayand corresponding pipe 92 to effect operation of switch 3 to its closedposition. In the closed position of normally open contact 95 of switch 3a circuit is established between a wire 96 that is connected to thehereinbefore-mentioned power supply wire 38 and a wire 97 that isconnected to an emergency relay (not shown) in the function selectorunit 15 to cause energization or pickup of this relay. Whenever thisrelay is picked up, transmission of the emergency brake applicationcommand signal to the slave locomotive is made via radio-transmittedsignals effected by the coding system 16, transmitter 17 and antenna 18.

The brake control valve 13 may be of any suitable type, such as, forexample, a 26-F type of brake control valve manufactured by theaforesaid Westinghouse Air Brake Division of Westinghouse Air BrakeCompany.

The function selector unit 15 may be, such as, for example, an A-3-Atype of selector unit manufactured by the aforesaid company.

The coding system 16, the transmitter 17, the receiver I9 and thedecoding system 20 are all embodied in a single coding cabinet andconstitute the No. 580 solid-state code system manufactured by theSignal 8: Communications Division of Westinghouse Air Brake Company.

The antenna 18 may be, such as, for example, a 6 AN-l antennamanufactured by Antenna Specialists Company. This antenna 18 isconnected to the transmitter 17 and receiver 19 by a suitable cable.

The selector and indicator console 21 may be such as, for example, anA-2 type of selector and indicator console manufactured by the aforesaidWestinghouse Air Brake Division of Westinghouse Air Brake Company.

The main reservoir 5 is charged with fluid under pressure by the usualfluid compressor (not shown) carried on the locomotive.

OPERATION Let it be supposed that a locomotive is provided with thebrake control apparatus shown in the drawings and that this locomotiveis the lead locomotive in an RMU train consist. Let it be furthersupposed that a locomotive is coupled between two cars in the trainwhich may be at a distance from the lead locomotive, and that the brakecontrol equipment on this slave locomotive includes, with the exceptionof the differential-pressure-operated master controller switch devices 1and 2, the same brake control equipment as shown in the drawings withthe addition of a brake control center, which may be, such as, forexample, an A-4l0 brake control center manufactured by the aforesaidWestinghouse Air Brake Division. It will be understood that this brakecontrol equipment on the slave locomotive is operative in response tothe radiotransmitted signals received from the lead locomotive tocontrol the pressure in the equalizing reservoir on this slavelocomotive and correspondingly the pressure in that portion of the trainbrake pipe extending in both directions from the slave locomotive.

After a train is made up, the lead and slave locomotive controlequipments must be conditioned as follows:

1. The controls on the lead locomotive set for lead operation.

2. The selector valve 49 of the brake valve 10 on both the lead and theslave locomotive set in freight position.

3. The power supply switch of the selector and indicator console 21shown in the drawings is set in power ON position, it being understoodthat a fluid pressure brake switch on this console 21 is set in an [Nposition, subsequent to the setting this power supply switch in itspower ON position.

4. The controls on the slave locomotive set for trailing operation,except for the fluid pressure brakes which must be set for leadoperation.

. The handle 93 of the automatic brake valve 10 and the handle 63 of theindependent brake valve 11 on the slave locomotive must be moved totheir brake release position.

6. The function selector unit on the remote locomotive set in power ONposition.

In order to initially effect charging of the brake pipe 9 on the leadlocomotive and the train brake pipe that extends back through each carin the train and the brake equipment on each of these cars, the engineeron the lead locomotive will manually move the handle 93 of the brakevalve 10 on this locomotive to its brake release positions.

Also, it may be assumed that a regulating spring 98 (FIG. 2) of theself-lapping control valve 46 of the brake valve 10 on both the leadandthe remote locomotive has been manually adjusted by means of anadjusting screw 99 so that this control valve 46 will provide in itsdelivery chamber 75 a desired normal pressure, which, for example, maybe 70 pounds per square inch.

It will be understood that while the selector valve 49 of the brakevalve 10 on each locomotive occupies its freight position, the supply offluid under pressure from the main reservoir on the respectivelocomotive to the corresponding equalizing reservoir cutoff valve 48will be effected only while the handle 93 occupies its brake releaseposition to cause opening of this valve. Consequently, fluid underpressure will flow from the delivery chamber 75 of the control valve 46of the brake valve on the lead locomotive to the correspondingequalizing reservoir 71 via passageway and corresponding pipe 74, pipe70 and choke 72. Fluid under pressure thus supplied to the pipe 70 alsoflows to the chamber 68 in the relay valve 45, via passageways 70 and 67whereupon this relay valve is operated to effect the supply of fluidunder pressure from the main reservoir 5 on the lead locomotive to thatpor tion of the train brake pipe connected to this locomotive.

Some of the fluid under pressure flowing to the passageway 67 from thepassageway and pipe 70 flows to the chamber 25 (FIG. 1) in the switchdevice 1 via the pipe 67. Fluid under pressure thus supplied to thischamber 25 is effective on the left-hand side of the correspondingdiaphragm 24 to deflect it in the direction of the right hand andthereby move the stem 28 in this same direction until the movablecontact 32 carried on the right-hand end of this stem is moved intocircuit-closing contact with the corresponding stationary contact 37 itbeing noted that the loop in the wire 43 provides for this movementwithout breaking the wire 43. In this circuit-closed position of thesecontacts 32 and 37 a circuit is established between the LII wire 40 thatis connected to the power supply wire 38 and the wire 43 that isconnected, as aforesaid, to the automatic brake release relay in thefunction selector unit 15 to cause energization or pickup of this relay.As hereinbefore explained, when this automatic brake release relay ispicked up, automatic brake release command signals are transmitted fromthe lead locomotive to the slave locomotive to the slave locomotive tocause the automatic brake valve 10 on this locomotive to effect thesupply of fluid under pressure to that portion of the train brake pipeconnected thereto. Consequently, the supply of fluid under pressure tothe train brake pipe is now simultaneously effected by operation of theautomatic brake valve 10 on both the locomotives in the train until thetrain brake pipe is charged to the normal pressure carried therein.

It will be noted from FIG. 1 of the drawings that fluid under pressuresupplied to the equalizing reservoir 71 via the choke 72 also flows tothe chamber 26 in the switch device 1 via the pipe 73 at a ratedetermined by the size of the choke 72 so that the chamber 26 is chargedwith fluid under pressure at a slower rate than the chamber 25.Consequently, it is apparent that the contacts 32 and 37 of the switchdevice 1 remain in their closed position until the pressure in thechamber 26 is increased to substantially that in the chamber 25 whichcorresponds to the setting of the control valve 46. Upon substantialequalization of pressure in the chambers 25 and 26, a pair of springsand 10], disposed on opposite sides of the diaphragm 24 and insurrounding relation to the stem 28, is rendered effective to move thediaphragm 24 and stem 28 to the position shown in FIG. I in which themovable contact 32 is moved out of circuit-closing contact with thestationary contact 37 thus opening the circuit to the automatic brakerelease relay in the function selector unit 15 to cause deenergizationof this relay.

Since the brake control valve 13 is connected to the brake pipe 9 by thebranch pipe 14, fluid under pressure will flow from the brake pipe 9 tothe brake control valve 13 to effect operation thereof to its releaseposition in which it causes fluid under pressure to be completelyreleased from the brake cylinder 4 thereby releasing the brakes on thelead locomotive, and in which it causes the auxiliary reservoir 6,control reservoir 7 and selector volume reservoir 8 to be charged to thepressure carried in the brake pipe 9. Likewise, the brake control valveson the slave locomotive and all the cars in the train will operate inresponse to charging of the train brake pipe to the normal pressurecarried therein, as determined by the setting of the control valve 46 ofthe automatic brake valve 10 on the two locomotives in the train, whichnormal pressure may be, for example, as hereinbefore stated, 70 poundsper square inch, to effect a complete release of the brakes on the twolocomotives and all the cars in the train.

The engineer on the lead locomotive may now start the train on itsjourney to the next terminal or station.

Let it be supposed that after the train has traveled some distance fromits starting point, it must descend a grade that requires that theengineer on the lead locomotive effect a brake application on the entiretrain. Accordingly, the engineer will move the handle 93 of theautomatic brake valve 10 on the lead locomotive out of its releaseposition and to a position in its application zone corresponding to thedegree of reduction of pressure desired in the train brake pipe.Therefore, the self-lapping control valve 46 of the automatic brakevalve 10 will now be operated in the usual manner in which an exhaustvalve 102 (FIG. 2), that is disposed in the chamber 75, is unseated fromits valve seat 103. When valve 102 is thus unseated, fluid underpressure flows from the chamber 25 (FIG. 1) in the switch device 1 andthe chamber 68 in the relay valve 45 to atmosphere at an unrestrictedrate via pipe and passageway 67, passageway and pipe 70, pipe andpassageway 74, chamber 75, past now unseated exhaust valve 102, a port104 in an exhaust valve seat member 105, a chamber 106 in a controlvalve cover 107, and a port 108 in this cover. Simultaneously, fluidunder pressure flows from the chamber 26 in the switch device I and theequalizing reservoir 71 to atmosphere at a restricted rate determined bythe size of the choke 72 via pipe 73, pipe 70 having choke 72 therein,pipe and passageway 74, chamber 75 and thence past the unseated exhaustvalve 102 to atmosphere via the pathway described above.

As explained above, fluid under pressure is now being vented from thechamber 25 in the switch device 1 at an unrestricted rate and from thechamber 26 in this switch device at a restricted rate. Accordingly, itis apparent that a pressure differential is quickly established on theopposite sides of the diaphragm 24 which pressure differential iseffective to deflect this diaphragm in the direction of the left handand thereby move the stem 28 in the same direction until the movablecontact 31 secured to the left-hand end of this stem is moved intocircuit-closing contact with the stationary contact 34. ln thiscircuit-closed position of these contacts 34 and 31, the hereinbeforedescribed circuit to the automatic brake application relay in thefunction selector unit 15 is supplied with electric power from the powersupply wire 38 to cause energization or pickup of this relay. When thisrelay is thus picked up, automatic brake application command signals aretransmitted from the lead to the slave locomotive via radio-transmittedsignals effected by operation of the coding system 16, transmitter 17and antenna 18. It will be understood that the brake control equipmenton the slave locomotive is operative in response to receiving thesesignals to effect a reduction of pressure in the equalizing reservoir onthis locomotive and a corresponding reduction of pressure in thoseportions of the train brake pipe connected thereto so long as theseradiotransmitted signals are received from the lead locomotive.

Fluid under pressure is released at an unrestricted rate from thechamber 25 in the switch device 1 and the chamber 68 in the relay 45 ofthe automatic brake valve on the lead locomotive to atmosphere via thepathway described above until the pressure in these chambers is reducedto a value corresponding to the position in its application zone towhich the handle 93 of the brake valve 10 was moved by the engineer. Atthe same time fluid under pressure, is released at a restricted ratefrom the chamber 26 in the switch device 1 and the equalizing reservoir71 to atmosphere until the pressure therein is reduced to a valuecorresponding to the position to which the handle 93 was moved, at whichtime the control valve 46 shifts to its lap position in which valve 102is seated on seat 103 to cut off further flow of fluid under pressure toatmosphere.

It will be understood that the relay valve 45 of the automatic brakevalve 10 on the lead locomotive operates in response to the release offluid under pressure from its chamber 68 to atmosphere to release fluidunder pressure from that portion of the train brake pipe connected tothe lead locomotive until the pressure therein is reduced the sameamount as the pressure in the chamber 68 and the equalizing reservoir 71is reduced by operation of the control valve 46.

It will be further understood that the above-mentioned release of fluidunder pressure from the chamber 26 in the switch device 1 at arestricted rate subsequent to the cessation of the release of fluidunder pressure from the chamber 25 in this switch device quickly reducesthe pressure in the chamber 26 to that in the chamber 25. Uponequalization of pressure in these chambers 25 and 26 in switch device 1,the corresponding springs 100 and 101 are rendered effective to shiftthe diaphragm 24, stem 28 and movable contact 31 to the position shownin FIG. 1 in which movable contact 31 is no longer in circuit-closingcontact with the stationary contact 34. This movement of contact 31 outof circuit-closing contact with contact 34 opens the circuit to theautomatic brake application relay in the function selector unit therebyterminating the transmission of automatic brake application signals fromthe lead locomotive to the slave locomotive whereupon the brake controlequipment on this locomotive operates to cor respondingly terminate thereduction of pressure in that portion or those portions of the trainbrake pipe connected to the slave locomotive. Accordingly, form theforegoing, it will be understood that operation of the brake controlvalves on both locomotives and all the cars in the train occurssubstantially simultaneously in response to the reduction of pressureeffected in the train brake pipe to effect a brake application on theentire train.

The brakes on the entire train can be subsequently released by theengineer on the lead locomotive manually moving the handle 93 of thebrake valve 10 on this locomotive out of the position it occupies in itsapplication zone and back to its brake release position. Upon return ofthe handle 93 to its brake release position, the corresponding controlvalve 46 (FIG. 2) operates to effect the supply of fluid under pressureto the equalizing reservoir 71 and chamber 63 in relay valve 45 on theleading locomotive whereupon this relay valve operates to effect thesupply of fluid under pressure from the main reservoir 5 on thislocomotive to that portion of the train brake pipe connected thereto.

The control valve 46 also supplies fluid under pressure at anunrestricted rate to the chamber 25 (FIG. 1) in the switch device 1 viapassageway and pipe 74, pipe and passageway 70 and passageway and pipe67 and to the chamber 26 in this switch device 1 at a restricted ratevia passageway and pipe 74, pipe 70, choke 72 and pipe 73. The morerapid supply of fluid under pressure to the chamber 25 quicklyestablishes a differential pressure force on the diaphragm 24 which actsin the direction of the right hand to deflect this diaphragm in the samedirection to cause the stem 28 to be shifted in the direction of theright hand until the contact 32 carried thereby is moved intocircuit-closing contact with the corresponding contact 37. This effectspickup of the automatic brake release relay whereupon the automaticbrake valve 10 on the slave locomotive is operated in the mannerhereinbefore described to effect the supply of fluid under pressure tothat portion of the train brake connected thereto. Consequently, thesupply of fluid under pressure to the train brake pipe is nowsimultaneously effected by operation of the automatic brake valve 10 onthe two locomotives in the train until the train brake pipe is chargedto the normal pressure carried therein, it being understood that therelay valve 45 and the switch device 1 on the lead locomotive operate inthe manner hereinbefore described to terminate the supply of fluid underpressure to the train brake pipe upon the pressure therein increasing tothis normal value.

Let it now be supposed that while the brakes on the entire train arereleased and the train is traveling along the track toward itsdestination it becomes necessary that the engineer on the leadlocomotive effect an emergency brake application.

To effect an emergency brake application on the entire train, theengineer on the lead locomotive will move the handle 93 of the automaticbrake valve 10 on this locomotive from its release position to itsemergency position to effect a reduction of pressure in the brake pipe 9and in that portion of the train brake pipe extending from the leadlocomotive toward the slave locomotive at a rapid or emergency rate. Thecontrol valve 13 on the lead locomotive operates in response to thisreduction of pressure in the brake pipe 10 at an emergency rate toeffect a corresponding emergency brake application on this locomotive.

When the handle 93 is manually moved by the engineer to its emergencyposition, the emergency valve of automatic brake valve 10 is moved to aposition to establish a communication via which fluid under pressure issupplied from the main reservoir 5 to the pipe 92 which is connected tothe switch 3, whereupon the contact 95 of this switch is moved to itsclosed position in which it closes the circuit between the wires 96 and97 to cause pickup of the hereinbefore-mentioned emergency relay in thefunction selector unit 15 on the lead locomotive in the mannerhereinbefore described.

As hereinbefore stated, when this emergency relay is thus picked up,transmission of the emergency application command signal to the slavelocomotive is made via radio-transmitted signals effected by the codingsystem 16, transmitter 17 and antenna 18 on the lead locomotive. It willbe understood that the brake control equipment on the slave locomotiveis operative in response to the emergency application command signalstransmitted thereto from the lead locomotive via radio signals to effecta reduction of pressure in the brake pipe 9 on the slave locomotiveand'in the portions of the train brake pipe extending from each end ofthis slave locomotive at an emergency rate. Accordingly, it will beunderstood that the brake control valves on the two locomotives and allthe cars in the train operate substantially simultaneously in responseto a reduction of pressure in the train brake pipe at an emergency rateto effect an emergency brake application on the entire train.

When the train has been brought to a stop and all danger has past, theemergency brake application can be released by the engineer moving thehandle 93 of the brake valve on the lead locomotive from its emergencyposition back to its release position.

Let it now be supposed that, while the brakes on the entire train arereleased, the engineer desires to manually effect an independent brakeapplication on the two locomotives by use of the independent brake valve11 on the lead locomotive. To do so, he will move the handle 63 of thisindependent brake valve Ill from its release position into a servicezone an extend corresponding to the degree of brake application desired.When the handle 63 is moved into the service zone, a cam 109 (FIG. 2) iscorrespondingly rotated to first effect seating of an exhaust valve 110on its corresponding valve seat 111 and then to effect unseating of asupply valve ll2 from its corresponding valve seat 113 in the usualwell-known manner of operation of self-lapping valve units. Upon theunseating of supply valve 112, fluid at main reservoir pressure willflow from the main reservoir 5 to the chamber 25 (FIG. 1) in the switchdevice 2 via pipe and passageway 53, past open valve 112, deliverychamber 77, and passageway and pipe 76. Some of the fluid under pressurethus supplied to the pipe 76 flows therefrom to the chamber 26 at arestricted rate via the pipe 78 and choke 79 and some of the fluid underpressure thus supplied to the pipe 78 flows to the volume reservoir 80via the choke 79 and pipe 81. Accordingly, it is apparent that the fluidunder pressure supplied at an unrestricted rate to the chamber 25 and ata restricted rate to the chamber 26 and volume reservoir 80 quicklyestablishes a differential fluid pressure force on the diaphragm 24 ofswitch device 2 to deflect this diaphragm in the direction of the righthand and thereby move the stem 28 in the same direction until themovable contact 32 carried on the right-hand end of this stem is movedinto circuit-closing contact with the corresponding stationary contact37. In this circuit-closed position of these contacts 32 and 37, theindependent brake application relay in the function selector unit isenergized or picked up to cause the transmission of the independentbrake application command signal to the slave locomotive. It will beunderstood that the brake control equipment on the slave locomotive isoperative in response to receiving these signals to effect the supply offluid under pressure to the brake cylinder on the slave locomotive toeffect an independent brake application on the slave locomotive.

Also, it will be noted from FIG. 1 of the drawings that some of thefluid under pressure supplied to the pipe 76 by the independent brakevalve 11 flows therefrom to the brake cylinder 4 on the lead locomotivevia pipe 82, double check valve 83 and pipe 85 to effect an independentbrake application on the lead locomotive substantially simultaneously asan independent brake application is effected on the slave locomotive.

Furthermore, it will be noted from FIG. 2 of the drawings that some ofthe fluid under pressure supplied to the passageway 76 will flowtherefrom to a chamber 114 at the left-hand side ofa diaphragm 115 via achoke M6 to cause the self-lapping valve unit 50 to operate to its lapposition when the pressure in the passageway and pipe 76 and in thebrake cylinder 4 (FIG. 1) on the lead locomotive, and also on the slavelocomotive, reaches a pressure corresponding to the position in itsapplication zone to which the handle 63 of independent brake valve 11was moved by the engineer.

Subsequent to movement of the self-lapping valve unit 50 to its lapposition, fluid under pressure will flow from the pipe 76 to the chamber26 in the switch device 2 and to the volume reservoir 80 via the choke79 and pipes 78 and 81 until the pressures in the chamber 25 and 26 andthe volume reservoir 80 substantially equalize whereupon thecorresponding springs and 101 are rendered effective to shift thediaphragm 24, stem 28 and contact 32 of switch device 2 to the positionshown in FIG. 1 to effect deenergization of the independent brakeapplication relay in the function selector unit 15 thereby terminatingthe transmission of independent brake application command signals fromthe lead to the slave locomotive. It will be understood that the brakecontrol equipment on the slave locomotive is operative upon cessation ofthe independent brake application command signals to prevent furthersupply of fluid under pressure to the corresponding brake cylinder.

To release the above-described independent brake application on the twolocomotives in the train, the engineer will return the handle 63 of theindependent brake valve 11 on the lead locomotive to its releaseposition. As the handle 63 is thus returned to its release position, theself-lapping valve unit 50 of the brake valve ll will operate in theusual way to completely release fluid under pressure from the passagewayand pipe 76, brake cylinder 4, and chamber 25 in the switch device 2 toatmosphere at an unrestricted rate. At the same time fluid underpressure will be released from the chamber 26 in the switch device 2 andthe volume reservoir 80 at a restricted rate via pipes 81 and 78, choke79, pipe and passageway 76 and the self-lapping valve unit 50.

It is apparent from the foregoing that a pressure differential isquickly established on the opposite sides of the diaphragm 24 whichpressure differential is effective to deflect this diaphragm in thedirection of the left hand and thereby shift stem 28 in this samedirection to move contact 31 into circuitclosing contact with contact34. In this circuit-closed position of these contacts 34 and 31 ofswitch device 2, the hereinbefore-described circuit to the independentquick-release relay in the function selector unit 15 is supplied withelectric power from the power supply wire 38 to cause pickup of thisrelay. In the manner aforesaid, pickup of this relay effectstransmission of the independent brake release command signal to theslave locomotive. It will be understood that the brake control equipmenton the slave locomotive is operative in response to receiving thesesignals to completely release all fluid under pressure from thecorresponding brake cylinder on the slave locomotive substantiallysimultaneously as fluid under pressure is completely released from thebrake cylinder 4 on the lead locomotive. Thus, an independent release ofthe brakes on the two locomotives in the train is effected.

Subsequent to the complete unrestricted release of fluid under pressurefrom the chamber 25 in the switch device 2 to atmosphere via the pathwaydescribed above, fluid under pressure will continue to flow at arestricted rate from the chamber 26 in this switch device 2 and thevolume reservoir 80 to atmosphere via pipes 81 and 78, choke 79, pipeand passageway 76 and the self-lapping valve 50 of the brake valve 11until all fluid under pressure is substantially released from chamber 26and volume reservoir 81 whereupon the corresponding springs and 101 arerendered effective to shift the diaphragm 24, stem 28 and movablecontacts 31, 32 to the position shown in FIG. 1 in which movable contact31 is no longer in circuit-closing contact with the stationary contact34. Thus, the circuit to the independent quick-release relay in thefunction selector unit 15 is opened to terminate the transmission of theindependent brake release command signal to the slave locomotive.

Let it be supposed that a partial or full service brake appli cation hasbeen effected on the two locomotives and all the cars in the train bymanual operation of the automatic brake valve device 10 on the leadlocomotive, in the manner hereinbefore described.

Also, let it be supposed that subsequent to effecting a partial or fullservice brake application on the two locomotives and all the cars in thetrain, the engineer desires to effect a release of the brakes only onthe two locomotives, without effecting a release of the brakes on thecars in the train.

To effect a release of the brakes on the two locomotives withouteffecting a release of the brakes on the cars in the train, the engineerwill depress the handle 63 (FIGS. 1 and 2) of the independent brakevalve device 11 on the lead locomotive so that it is rocked clockwiseabout the pin 64 (FIG. 2). As the handle 63 is depressed, the roller 65carried thereby is effective, through intermediary of the pusher stem66, to move the release valve 51 downward from the position shown inFIG. 2 to a position in which the peripheral annular groove 57 on therelease valve 51 closes communication between the actuating pipe andpassageway 55 and the atmospheric vent port 56, and establishes acommunication between the actuating pipe and passageway 55 and thepassageway and pipe 53 which is connected to main reservoir 5.Therefore, when the release valve 51 is thusmoved to its lower positionby the engineer manually depressing the handle 63 of the independentbrake valve 11, fluid under pressure will flow from the main reservoirto the release selector valve portion of the quickrelease valve of thebrake control valve 13 on the lead locomotive via pipe and passageway53, groove 57 on independent release valve 51, and passageway and pipe55 to effect a release of the brakes only on the lead locomotive.

As can be seen from FIG. 1, some of the fluid under pressure supplied tothe pipe 55 in the manner described above flows therefrom to thefluid-pressure-operated switch 59 via the pipe 58 to move the contact 60of this switch to its closed position to establish the circuit betweenthe wires 61 and 62. When this circuit is thus established, theindependent quickrelease relay in the function selector unit 15 isenergized or picked up to effect transmission of the independent brakerelease command signal to the slave locomotive or locomotives in themanner hereinbefore described to cause a release of the brakes only onthis slave locomotive substantially simultaneously as the brakes arereleased on the lead locomotive.

Referring to FIG. 3 of the drawings, a modified arrangement of a brakecontrol equipment for a locomotive when it is used as the leadlocomotive in remote multiple unit operation is shown which differs fromthe first embodiment of the invention shown in FIG. 1 by the eliminationof the choke 72 from the pipe 70 (FIGS. 1 and 2) and the interpositionof a choke 117 (FIG. 3) in the pipe 73 and the addition ofa supplementalvolume reservoir 118 which is connected to the pipe 73 on the right-handor downstream side of the choke 117 by a short pipe 119. This secondembodiment of the invention further differs from the first embodimentshown in FIG. 1 in that the chamber 25 in the switch device 1 isconnected to the pipe 73 on the left-hand or upstream side of the choke117 by a pipe 20. The purpose of elimination of the choke 72 and theaddition of the choke 117 is to, respectively, assure an unrestrictedrate of supply of fluid under pressure to and the release of fluid underpressure from the equalizing reservoir 71 and chamber 25 in switchdevice 1, and a restricted rate of supply of fluid under pressure to andthe release of fluid under pres sure from the chamber 26 in this switchdevice so that this switch device 1 shown in FIG. 3 functions the sameas the switch device 1 shown in FIG. 1. Accordingly, like referencenumerals have been used to designate the structure shown in FIG. 3 whichis identical with that shown in FIG. 1 and already described.

The operation of the locomotive brake control equipment shown in FIG. 3is substantially the same as that of the locomotive brake controlequipment shown in FIG. 1. Hence, a detailed description. of theoperation of the brake control equipment shown in FIG. 3 is not deemednecessary.

Having now described the invention, what I claim as new and desire tosecure by Letters Patent, is:

Iclaim:

I. In a multiple locomotive brake control system for a train of carshaving a lead locomotive and at least one slave locomotive remotelylocated therefrom, brake control apparatus for the lead locomotivecomprising the combination of:

a. a normally charged brake pipe variations of the fluid pressure inwhich are effective to control brake applications and brake releases onthe locomotives and cars in the train,

b. a normally charged equalizing reservoir,

c. a brake valve having:

i. a relay valve which is subject to the opposing pressures in saidequalizing reservoir and said brake pipe and is operative by thedifferential of such pressures to control the pressure in said brakepipe, and

ii. regulating valve means operative to control the pressure in saidequalizing reservoir, and

d. coding and radio signal transmitting means for transmitting commandsignals from the lead locomotive to a slave locomotive, wherein theimprovement comprises:

e. means controlled according to the operation of the brake valve forcorrespondingly controlling operation of the coding and radio signaltransmitting means.

2. In a multiple locomotive brake control system for a train of cars,the combination as claimed in claim 1, further characterized in that thelast said means comprises a fluid-pressureoperated switch deviceoperated accordingly as said brake valve is selectively manuallyoperated to corresponding ones of a plurality of operating positions.

3. In a multiple locomotive brake control system for a train of cars,the combination as claimed in claim 2, further characterized in thatsaid switch device comprises:

a. an abutment subjected to fluid pressure on opposite sides thereof andmovable in opposite directions from a neutral position respectivelyaccording to the predominating pressure acting thereon, and

b. a pair of normally open switches disposed on opposite sidesrespectively of the abutment and operative selectively to closedpositions upon movement of said abutment out of its neutral position inthe direction of the switch, and in that c. said regulating valve meansis effective upon operation thereof to supply fluid under pressure to orrelease fluid under pressure from both sides of said abutmentsimultaneously, and

d. said system including choke means restricting the supply and releaseof fluid under pressure to and from the chamber at one side of saidabutment.

4. In a multiple locomotive brake control system for a train of cars,the combination as claimed in claim 3, further characterized in thatsaid switch device comprises biasing means operable upon substantialequalization of pressure on opposite sides of its abutment to move saidabutment to its neutral position in which the said switches are restoredto normally open position.

5. In a multiple locomotive brake control system for a train of cars,the combination as claimed in claim 3, further characterized by volumemeans communicating with the chamber on the said one side of saidabutment.

6. In a multiple locomotive fluid pressure brake control system forcontrolling braking of a train of cars having a lead locomotive and atleast one slave locomotive remotely located therefrom, brake controlapparatus for the lead locomotive comprising the combination of:

a. a normally charged brake pipe, variations of the fluid pressure inwhich are effective to control brake applications and brake releases onthe locomotives and cars in the train;

b. a normally charged equalizing reservoir;

c. an automatic brake valve having:

i. a relay valve which is subject to the opposing pressures in saidequalizing reservoir and said brake pipe and is operative by thedifferential of such pressures to control the pressure in said brakepipe, and

ii. regulating valve means operative to control the pressure in saidequalizing reservoir;

(1. a brake-applying means;

e. control valve means for supplying fluid under pressure to andreleasing fluid under pressure from the brake-applying meansresponsively to variations of pressure in the brake pipe;

an independent brake valve having:

i. a self-lapping valve means, operable to supply fluid under pressureto and release fluid under pressure from the brake-applying means, and

ii. manually operable means for effecting operation of said self-lappingvalve means to supply fluid at different pressures to saidbrake-applying means;

coding and radio signal transmitting means for transmitting commandsignals from the lead locomotive to a slave locomotive, wherein theimprovement comprises:

h. first means controlled according to the operation of said automaticbrake valve for correspondingly controlling operation of the coding andradio signal transmitting means; and

i. second means controlled according to the operation of saidindependent brake valve for also corresponding controlling operation ofthe coding and radio signal trans mitting means.

7. In a multiple locomotive brake control system for a train of cars,the combination as claimed in claim 6, further characterized in thateach of said means comprises:

a. an abutment subjected to fluid pressure on opposite sides thereof andmovable in opposite directions from a neutral position respectivelyaccording to the predominating pressure acting thereon, and

b. a pair of normally open switches disposed on opposite sidesrespectively of the abutment and operated selectively to closedpositions upon movement of said abutment out of its neutral position inthe direction of the switch, and in that c. said regulating valve meansis effective upon operation thereof to supply fluid under pressure to orrelease fluid under pressure from both sides of the abutment of saidfirst means simultaneously, and said self-lapping valve means iseffective upon operation thereof to supply fluid under pressure to orrelease fluid under pressure from both sides of the abutment of saidsecond means simultaneously, and

d. said system further including first choke means restricting thesupply and release of fluid under pressure to and from the chamber atone side of said abutment of said first means, and

e. second choke means restricting the supply and release of fluid underpressure to and from the chamber at one side of said abutment of saidsecond means.

8. In a multiple locomotive brake control system, the combination asclaimed in claim 7, further characterized in that the chamber at saidone side of the abutment of said first means communicates directly withsaid equalizing reservoir and the chamber on the other side of saidabutment communicates with said equalizing reservoir via said firstchoke means.

9. In a multiple locomotive brake control system for a train of cars,the combination as claimed in claim 7, further characterized by volumemeans communicating directly with the chamber at the said one side ofsaid abutment of said second means for increasing the volume of thischamber above the volume of the chamber on the other side of saidabutment.

10. In a multiple locomotive brake control system for a train of cars,the combination as claimed in claim 7, further characterized in thatsaid equalizing reservoir is directly connected to the chamber at thesaid one side of the abutment of said first means, and a volumereservoir is directly connected to the chamber at the said one side ofthe abutment of said second means,

11. ln a multiple locomotive brake control system for a train of cars,the combination as claimed in claim 7, further characterized in that thechoke means for said first means is interposed between the chambers atopposite sides of the abutment of the first means, a volume reservoir isconnected to the chamber at the said one side of said abutment of thefirst means, and said equalizing reservoir is connected directly to thechamber at the other side of said abutment of the first means.

12. In a multiple locomotive brake control system for a train of cars,the combination as claimed in claim 3, further characterized in that oneswitch of said pair ofswitches, while closed, causes operation of saidcoding and radio signal transmitting means to transmit a brakeapplication command signal to a slave locomotive, and in that the otherswitch of said pair of switches, while closed, causes operation of saidcoding and radio signal transmitting means to transmit a brake releasecommand signal to a slave locomotive.

13. In a multiple locomotive brake control system for a train of cars,the combination as claimed in claim 7, further characterized in that:

a. one switch of said pair of switches of said first means, whileclosed, establishes a circuit to cause operation of said coding andradio transmitting means to transmit an automatic brake applicationcommand signal to a slave locomotive,

b. the other switch of said pair of switches of said first means, whileclosed, establishes a circuit to cause operation of said coding andradio transmitting means to trans mit an automatic brake release commandsignal to a slave locomotive,

c. one switch of said pair of switches of said second means, whileclosed, establishes a circuit to cause operation of said coding andradio transmitting means to transmit an independent brake releasecommand signal to a slave locomotive, and

d. the other switch of said pair of switches of said second means, whileclosed, establishes a circuit to cause opera tion of said coding andradio transmitting means to transmit on an independent brake applicationsignal to a slave locomotive.

